I feel like my boyfriend is falling out of love with me..

I've known my boyfriend for 3 years and we've been dating for 1 1/2 years. He is my world. We're in a long distance relationship because he is currently in the navy. But things have been different with us. We fight a lot, and I just feel like things aren't the same. I know he has a lot on his plate but he's never acted this way before. I still feel everything for him. All those mushy, love feelings, but I don't think he does. I got upset over FaceTime because he was being a bit rude and I told him that I feel like he doesn't feel the same about me anymore and he got mad and it turned into another argument. I don't know what to do anymore.. I'm just trying all I can to make him happy but it's been hard.. very hard.